The invention relates to vehicle seats, particularly seats for automobiles and light trucks, but is also applicable to heavy vehicles or aircraft. The seats of this invention will provide increased occupant protection in the event of a rollover accident, or other situations requiring repositioning of the head/chest. Rollover accidents occur relatively slowly compared to other accidents, such as front, side, or rear impacts. Thus rollover accidents can utilize additional design techniques to achieve occupant protection. Rollover occupant protection system design involves the integration of a number of components in the vehicle, all of which must be compatible with each other. One element of the vehicle available to vehicle designers in developing effective rollover occupant protection system designs is the seat with integral restraint. One element of the vehicle that is particularly hazardous to restrained occupants is the intruding roof. This invention moves the occupant's head and chest away from the vehicle roof automatically during a rollover.
It has been known in the art for some time, recognized by the inventors for almost ten years, that an important tool available to designers of occupant safety in a rollover, along with, for example, stronger roof structures, better occupant packaging, more effective restraint systems, active or passive rollbars and other available technology, is to dynamically move the occupant away from the roof before the roof crushes. In large vehicles such as semi-truck cabs, there is room to move the entire seat straight down a large distance away from the roof, and several approaches for this problem have been proposed. In co-pending application, Ser. No. 10/807,325, by the same inventor, three concepts for accomplishing rollover protection in light passenger vehicles with power (electric) integrated seats (all-belts to seats) are identified: dynamically tilt the seat back rearward in order to effectively move the occupant's head away from the roof and rearward in the vehicle, reorienting the torso-head/neck complex to a more advantageous position and orientation; compress the seat back and seat cushion to be smaller than their normal dimensions to increase headroom in conjunction with rollover actuated pretensioning seatbelts; and, under certain circumstances move the seat cushion forward or rearward or laterally to better position the occupant relative to the roof structure and/or to allow for the downward deployment of the seat back in restricted compartment space conditions. However, many vehicle seats do not have powered adjustment for reclining. The current invention addresses rollover safety for seats without power reclining capability.
Although solutions to some of the concepts have been previously proposed, none have been implemented in light vehicles to date. As described in co-pending application, Ser. No. 10/807,325, the existing solutions are not compatible with power adjustable seats. However even for non-powered seats, previously proposed solutions are not, in fact, practical, because they do not address characteristics of real manual seat designs either.
The reclining mechanism on almost all manual seats includes a ratchet, gear, or scissor type positioning mechanism, where a mechanical stop is engaged in a detent. This stop is manually moved by a lever or other release mechanism. The seat is moved to the desired position, and then the stop is re-engaged in different detent, holding the seat in the desired position. In addition, many seats have stops that limit the reclining motion. Both the limiting stops and adjustment stops, typically, should be strong mechanically. Existing solutions for rollover protection that rely on reclining the seat back to move the occupant away from the roof do not address the issue of the recliner adjustment or limiting stops, and therefore cannot be implemented in conventional seat designs.